This applet demonstrates what happens to a nematic crystal
molecule (that is, a single molecule in a Liquid Crystal Display)
when a current passes through it, and how that affects the polarization
of light.

The idea is that the field makes the molecule rotate, and as it does
it presents a smaller profile to the incoming light. This reduces
the amount it polarizes the light, and the light "untwists".

The polarization effect is greatly exaggerated to show the effect. In
reality each molecule only twists the light a minute amount.